No. 85.] 5,5 



a limited extent, each of the 14 simple elementary substances which 

 form a wheat plant. 



The organized arrangement of the phosphate of lime and magnesia, 

 in an embryo corn plant, and the locality of the salts of iron, zeine 

 and starch, are worth knowing. The following diagram illustrates 

 the section of a grain of corn ; 



a. The cotyledon or embryo. 



b. Starch. 



c. e. Oil — zeine — sugar. 



d. Salts of iron. 



In the cotyledon or germ, is deposited the phosphates which form 

 the bones of animals, and also most of the glutinous substance which 

 is indispensable in the formation of lean meat, tendon, tissue, and the 

 jelly found in bones. Hence, when the mouse eats out the chit of a 

 kernel of corn, he gets the raw material to make muscle, bone, and 

 brain ; and by taking into its stomach the iron in the dotted line d. 

 this little animal, as well as the ox and man, obtain the substance 

 which gives color to the blood, and with oxygen, the vital heat of the 

 system. 



The iron in venous blood, is in a state of protoxide. This fluid is 

 loaded with carbon, if not carbonic acid. From these causes venous 

 blood is much darker colored than arterial blood. In the latter the 

 iron is a peroxide, imparting to the blood a light vermillion hue. The 

 fact has often been demonstrated, that the air expelled from the lungs 

 of a warm blooded animal contains 100 times more carbonic acid than 

 the air taken into these organs. As the arteries leading from the 

 heart penetrate every part of the living frame, they convey vital gas 

 — oxygen, condensed in the peroxide of iron — to every portion of the 

 system. This oxygen, while the blood is passing through the tissues 

 from the arteries into the veins, combines with that portion of carbon 

 which has performed its office in nourishing the body, and carries it, 

 in the form of carbonic acid, through the veins, heart and lungs, into 

 the ever moving atmosphere. 



In thus burning the waste carbon in the system, ox3^gen gives out 

 just as much heat to the surrounding matter as it would, provided an 

 equal quantity of vital gas had burnt an equal amount of fuel in a 

 stove. 



